Don't take this the wrong way because I'm not trying to discourage you from your plans. By all means, do try it out, it might work great (and if it does, please share on here!)
That being said, I just want to clarify what I meant before about the focal length problem. It really has nothing to do with DOF or anything like that. It has more to do with framing. For example a longer focal length is going to make your subject appear closer to your background/other subject, whereas a shorter one will make them seem farther apart. It's also going to effect how much you are able to get in the frame while maintaining the angle you are visualizing.
I agree with you though, that you should steer clear of software. They have large learning curves and really are no easier for a complete beginner than teaching yourself to draw with pencil and paper.
In the end, do what works for you! Best of luck with the project